Mental Health Expert Witnesses In The R. V. Mohan Case

Expert witnesses are useful to courts in order to help determine the right sentence for an accused (Pozullo et al,. 2016). However, mental health expert witnesses have always been controversial in the justice system,
In order to figure out if an expert testimony should be accepted in court, Canadian courts follow the Mohan criteria (Pozullo et al., 2016). The list of criteria was established due to the R. v. Mohan case, in 1994 (Pozullo et al., 2016). Mohan was a pediatrician accused of sexually assaulting female teenage patients (Pozullo et al., 2016). In order to prove to the courts that he was not a pedophile, Mohan wanted to provide, as a mental health expert, a psychiatrist, to disprove the previous accusation (Pozullo et al., 2016).
When it was crafted, the Mohan criteria had four admissibility criteria that were emphasized (Pozullo et al., 2016). Firstly, the evidence provided by the expert witness must be relevant, meaning that it has to make "a fact at the issue of the case more or less likely" (Pozullo et al., 2016). Secondly, the evidence must be necessary in assisting the person, or group of people, also known as the trier of fact, in the legal proceedings (Pozullo et al., 2016). This criterion is necessary since the expert witness should provide information that is beyond the general understanding of the jury or judge (Pozullo et al., 2016). Further, the evidence should be provided without interfering with exclusionary rules, such as rules that would consider the evidence as invalid (Pozullo et al. 2016). Lastly, the expert witness must be qualified in order to
They have the ability to provide, compared to the other witnesses, their own opinions concerning facts of the case (Pozullo et al., 2016). Further, their role is to know not only their own testimony, but also be knowledgeable of how they fit in the court proceedings and what their presence implicates (Pozullo et al., 2016). For example, the expert witness must know what restrictions are applied to their behaviour in court (Pozullo et al., 2016). Through educating the trier of fact, these witnesses help them decide the sentence that is best suited for the accused, if said accused is found to be guilty. Expert witnesses, such as psychologists, help determine if the accused should be imprisoned (Pozullo et al., 2016). Mental expert witnesses based their judgment on the mental state of the offender when the crime occurred as well as their mental health history, for example, past drug abuse or psychosis diagnosis (Pozullo et al.,